trans_dsp16_twiddle_factors.h File Reference


Detailed Description

16-bit twiddle factors table

This file define the twiddle factors table

Author:
Atmel Corporation: http://www.atmel.com
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Definition in file trans_dsp16_twiddle_factors.h.

#include "dsp.h"

Go to the source code of this file.

Defines

Twiddle factors table
#define DSP16_N_TWIDDLE_FACTORS   1024
 This constant defines the size of the twiddle factors table we want to store in memory.
i.e.: if we want to compute a 1024-point (or less) complex FFT, we will define this constant as follow:.

Variables

TWIDDLE_FACTORS_PREFIX_TAB dsp16_t dsp16_twiddle_factors []
 This constant permits you to add attributes to the twiddle factors table.
It is useful if you want to store the table into another memory for example.
i.e.:.
TWIDDLE_FACTORS_PREFIX_TAB dsp16_t dsp16_twiddle_factors2 []
 This table has been generated using the following algorithm:.


Variable Documentation

TWIDDLE_FACTORS_PREFIX_TAB dsp16_t dsp16_twiddle_factors2[]

This table has been generated using the following algorithm:.

 for i=0:4:DSP16_N_TWIDDLE_FACTORS-4,
 k = i/(DSP16_N_TWIDDLE_FACTORS*4);
 w2 = exp(-2*PI*%i*k*2);
 w3 = exp(-2*PI*%i*k*3);
 end;
It is a one dimensional array containing the real parts (4*i parts) and imaginary parts (4*i+1 parts) of the w2 value and the real parts (4*i+2 parts) and imaginary parts (4*i+3 parts) of the w3 value.

Definition at line 598 of file trans_dsp16_twiddle_factors.c.

Referenced by dsp16_trans_complexfft(), dsp16_trans_complexifft(), and dsp16_trans_realcomplexfft().


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